package main

import (
	"fmt"
	"time"
)

type ChademoEvent interface {
	// GetValue Return processed/calculated value and timestamp string
	GetValue() (interface{}, *time.Time)
}

type frame struct {
	*CanFrame
}

// MaximumBatteryVoltage The maximum voltage value at the vehicle inlet terminals, at which the station stops charging to protect the vehicle battery
type MaximumBatteryVoltage frame

// ConstChargingRateInd Fixed value for charging rate indication, which is the maximum charging rate (100 %) 	of vehicle battery
type ConstChargingRateInd frame

// BatteryCapacity Rated capacity of battery
type BatteryCapacity frame

// MaxChargingTimeS Maximum charging time permitted by EV, set by 10 s
type MaxChargingTimeS frame

// MaxChargingTimeM Maximum charging time permitted by EV, set by minute
type MaxChargingTimeM frame

// EstChargingTimeM Estimated remaining time before the end of charging calculated by EV
type EstChargingTimeM frame

// EVControlProtocolNumber Software version of control protocol to which EV corresponds
type EVControlProtocolNumber frame

// TargetBatteryVoltage Target battery voltage ed charging voltage at the vehicle inlet terminals
type TargetBatteryVoltage frame

// ChargingCurrentReq Current value requested by EV during charging
type ChargingCurrentReq frame

// ChargingRate Charging rate of vehicle battery
type ChargingRate frame

// VehicleCharging Status flag indicating charge permission status of EV
type VehicleCharging frame

// ShiftLever Status flag indicating the shift lever position
type ShiftLever frame

// ChargingSystemFault Status flag indicating Charging system fault a malfunction caused by EV or the station, and detected by EV
type ChargingSystemFault frame

// VehicleStatus Status flag indicating the EV contactor status
type VehicleStatus frame

// NormalStopReq Status flag indicating the request of EV to stop charging control
type NormalStopReq frame

// BattOvervoltage Status flag indicating whether or not the vehicle battery voltage exceeds the maximum limit specified by EV
type BattOvervoltage frame

// BattUndervoltage Status flag indicating whether or not the vehicle battery voltage is less than the lower limit specified by EV
type BattUndervoltage frame

// BattCurrentDeviationErr Status flag indicating whether or not the output current deviates from EV requested current
type BattCurrentDeviationErr frame

// HighBattTemperature Status flag indicating whether or not the temperature of vehicle battery exceeds the maximum limit
type HighBattTemperature frame

// BattVoltageDeviationErr Status flag indicating whether or not the vehicle battery voltage deviates from the output voltage measured by the station
type BattVoltageDeviationErr frame

// EVSE entity from here

// EVcontWeldingDetectSupport Identifier indicating whether or not the station deals with EV contactor welding detection
type EVcontWeldingDetectSupport frame

// AvailableOutputVoltage Maximum output voltage value at the vehicle connector terminals
type AvailableOutputVoltage frame

// AvailableOutputCurrent Maximum output current value of the station
type AvailableOutputCurrent frame

// ThresholdVoltage Threshold voltage to stop the charging process in order to protect vehicle battery
type ThresholdVoltage frame

// EVSEControlProtocolNumber Software version number of control protocol or charging sequences that the station deals with
type EVSEControlProtocolNumber frame

// OutputVoltage Supply voltage value of the output circuit in the station
type OutputVoltage frame

// OutputCurrent Supply current value of the output circuit in the station
type OutputCurrent frame

// RemainingChargingTimeS Remaining time before the end of charging (counted by 10 s)
type RemainingChargingTimeS frame

// RemainingChargingTimeM Remaining time before the end of charging (counted by min)
type RemainingChargingTimeM frame

// StationStatus Status flag indicating the energy transfer from the station
type StationStatus frame

// StationMalfunction Status flag indicating whether or not there is a malfunction caused by the station
type StationMalfunction frame

// VehicleConnectorLock Status flag indicating Vehicle connector lock the electromagnetic lock status of vehicle connector
type VehicleConnectorLock frame

// BatteryIncompatibility Status flag indicating the compatibility of vehicle battery with the output voltage of station
type BatteryIncompatibility frame

// ChargingSystemMalfunction Status flag indicating whether or not there is a problem with EV, such as improper connection
type ChargingSystemMalfunction frame

// ChargerStopControl Status flag indicating whether or not the station proceeds with shutdown process
type ChargerStopControl frame

func FromCanFrames(frames <-chan *CanFrame) <-chan ChademoEvent {
	events := make(chan ChademoEvent)

	go func() {
		defer close(events)

		for frame := range frames {
			switch frame.canid {
			case CAN_ID_100:
				events <- &MaximumBatteryVoltage{frame}
				events <- &ConstChargingRateInd{frame}
			case CAN_ID_101:
				events <- &BatteryCapacity{frame}
				events <- &MaxChargingTimeS{frame}
				events <- &MaxChargingTimeM{frame}
				events <- &EstChargingTimeM{frame}
			case CAN_ID_102:
				events <- &EVControlProtocolNumber{frame}
				events <- &TargetBatteryVoltage{frame}
				events <- &ChargingCurrentReq{frame}
				events <- &ChargingRate{frame}
				events <- &VehicleCharging{frame}
				events <- &ShiftLever{frame}
				events <- &ChargingSystemFault{frame}
				events <- &VehicleStatus{frame}
				events <- &NormalStopReq{frame}
				events <- &BattOvervoltage{frame}
				events <- &BattUndervoltage{frame}
				events <- &BattCurrentDeviationErr{frame}
				events <- &HighBattTemperature{frame}
				events <- &BattVoltageDeviationErr{frame}
			case CAN_ID_108:
				events <- &EVcontWeldingDetectSupport{frame}
				events <- &AvailableOutputVoltage{frame}
				events <- &AvailableOutputCurrent{frame}
				events <- &ThresholdVoltage{frame}
			case CAN_ID_109:
				events <- &EVSEControlProtocolNumber{frame}
				events <- &OutputVoltage{frame}
				events <- &OutputCurrent{frame}
				events <- &RemainingChargingTimeS{frame}
				events <- &RemainingChargingTimeM{frame}
				events <- &StationStatus{frame}
				events <- &StationMalfunction{frame}
				events <- &VehicleConnectorLock{frame}
				events <- &BatteryIncompatibility{frame}
				events <- &ChargingSystemMalfunction{frame}
				events <- &ChargerStopControl{frame}
			}
		}
	}()

	return events
}

func getVehicleShiftLever(bytes *[]byte) ShiftLeverPosition {
	if isBitSet((*bytes)[5], 1) {
		return OTHER
	}
	return PARKING
}

func getVehicleStatus(bytes *[]byte) ContactorVehicleStatus {
	if isBitSet((*bytes)[5], 3) {
		return CONTACTOR_OPEN
	}
	return CONTACTOR_CLOSED
}

func getNormalStopReq(bytes *[]byte) StopRequest {
	if isBitSet((*bytes)[5], 4) {
		return STOP_REQUEST
	}
	return NO_REQUEST
}

func getFault(bytes *[]byte, octet byte, bit byte) SystemFault {
	if isBitSet((*bytes)[octet], bit) {
		return FAULT
	}
	return NORMAL
}

func getVehicleCharging(bytes *[]uint8) VehicleChargingEnabled {
	if isBitSet((*bytes)[5], 0) {
		return ENABLED
	}
	return DISABLED
}

func isBitSet(buf uint8, num uint8) bool {
	mask := uint8(1) << num
	val := buf & mask
	if val == mask {
		return true
	}
	return false
}

func bytesToUint16(bytes []uint8) uint16 {
	if len(bytes) != 2 {
		fmt.Println("Wrong array size in bytesToUint16()")
		return 0
	}

	var result uint16
	result = uint16(bytes[1]) << 8
	result = result | uint16(bytes[0])
	return result
}

func evWeldingDetectionSupport(bytes *[]uint8) SuppVehicleWeldingDetection {
	if (*bytes)[0] == 0 {
		return VEHICLE_WELDING_DETECTION_NOT_SUPPORTED
	}
	return VEHICLE_WELDING_DETECTION_SUPPORTED
}

func getStationState(bytes *[]uint8) StationState {
	if isBitSet((*bytes)[5], 0) {
		return CHARGING
	}
	return STANDBY
}

func getConnectorLock(bytes *[]byte) ConnectorLock {
	if isBitSet((*bytes)[5], 2) {
		return CONNECTOR_LOCKED
	}
	return CONNECTOR_UNLOCKED
}

func getBatteryCompatibility(bytes *[]uint8) BatteryCompatible {
	if isBitSet((*bytes)[5], 3) {
		return BATTERY_INCOMPATIBLE
	}
	return BATTERY_COMPATIBLE
}

func getChargerStopControl(bytes *[]uint8) StopControl {
	if isBitSet((*bytes)[5], 5) {
		return SHUTDOWN_STOP
	}
	return OPERATING
}

func (m MaximumBatteryVoltage) GetValue() (interface{}, *time.Time) {
	return bytesToUint16((*m.payload)[4:6]), m.date
}

func (c ConstChargingRateInd) GetValue() (interface{}, *time.Time) {
	return (*c.payload)[6], c.date
}

func (b BatteryCapacity) GetValue() (interface{}, *time.Time) {
	return 0.1 * float32(bytesToUint16((*b.payload)[5:7])), b.date
}

func (m MaxChargingTimeS) GetValue() (interface{}, *time.Time) {
	return 10 * uint16((*m.payload)[1]), m.date
}

func (m MaxChargingTimeM) GetValue() (interface{}, *time.Time) {
	return (*m.payload)[2], m.date
}

func (e EstChargingTimeM) GetValue() (interface{}, *time.Time) {
	return (*e.payload)[3], e.date
}

func (c EVControlProtocolNumber) GetValue() (interface{}, *time.Time) {
	return (*c.payload)[0], c.date
}

func (t TargetBatteryVoltage) GetValue() (interface{}, *time.Time) {
	return bytesToUint16((*t.payload)[1:3]), t.date
}

func (c ChargingCurrentReq) GetValue() (interface{}, *time.Time) {
	return (*c.payload)[3], c.date
}

func (c ChargingRate) GetValue() (interface{}, *time.Time) {
	return (*c.payload)[6], c.date
}

func (s ShiftLever) GetValue() (interface{}, *time.Time) {
	return getVehicleShiftLever(s.payload), s.date
}

func (v VehicleCharging) GetValue() (interface{}, *time.Time) {
	return getVehicleCharging(v.payload), v.date
}

func (c ChargingSystemFault) GetValue() (interface{}, *time.Time) {
	return getFault(c.payload, 5, 2), c.date
}

func (v VehicleStatus) GetValue() (interface{}, *time.Time) {
	return getVehicleStatus(v.payload), v.date
}

func (n NormalStopReq) GetValue() (interface{}, *time.Time) {
	return getNormalStopReq(n.payload), n.date
}

func (b BattOvervoltage) GetValue() (interface{}, *time.Time) {
	return getFault(b.payload, 4, 0), b.date
}

func (b BattUndervoltage) GetValue() (interface{}, *time.Time) {
	return getFault(b.payload, 4, 1), b.date
}

func (b BattCurrentDeviationErr) GetValue() (interface{}, *time.Time) {
	return getFault(b.payload, 4, 2), b.date
}

func (h HighBattTemperature) GetValue() (interface{}, *time.Time) {
	return getFault(h.payload, 4, 3), h.date
}

func (b BattVoltageDeviationErr) GetValue() (interface{}, *time.Time) {
	return getFault(b.payload, 4, 4), b.date
}

func (e EVcontWeldingDetectSupport) GetValue() (interface{}, *time.Time) {
	return evWeldingDetectionSupport(e.payload), e.date
}

func (a AvailableOutputVoltage) GetValue() (interface{}, *time.Time) {
	return bytesToUint16((*a.payload)[1:3]), a.date
}

func (a AvailableOutputCurrent) GetValue() (interface{}, *time.Time) {
	return (*a.payload)[3], a.date
}

func (t ThresholdVoltage) GetValue() (interface{}, *time.Time) {
	return bytesToUint16((*t.payload)[4:6]), t.date
}

func (e EVSEControlProtocolNumber) GetValue() (interface{}, *time.Time) {
	return (*e.payload)[0], e.date
}

func (o OutputVoltage) GetValue() (interface{}, *time.Time) {
	return bytesToUint16((*o.payload)[1:3]), o.date
}

func (o OutputCurrent) GetValue() (interface{}, *time.Time) {
	return (*o.payload)[3], o.date
}

func (r RemainingChargingTimeS) GetValue() (interface{}, *time.Time) {
	return (*r.payload)[6] * 10, r.date
}

func (r RemainingChargingTimeM) GetValue() (interface{}, *time.Time) {
	return (*r.payload)[7], r.date
}

func (s StationStatus) GetValue() (interface{}, *time.Time) {
	return getStationState(s.payload), s.date
}

func (s StationMalfunction) GetValue() (interface{}, *time.Time) {
	return getFault(s.payload, 5, 1), s.date
}

func (v VehicleConnectorLock) GetValue() (interface{}, *time.Time) {
	return getConnectorLock(v.payload), v.date
}

func (b BatteryIncompatibility) GetValue() (interface{}, *time.Time) {
	return getBatteryCompatibility(b.payload), b.date
}

func (c ChargingSystemMalfunction) GetValue() (interface{}, *time.Time) {
	return getFault(c.payload, 5, 4), c.date
}

func (c ChargerStopControl) GetValue() (interface{}, *time.Time) {
	return getChargerStopControl(c.payload), c.date
}